Drill



A. L. HAWKESWORTH.

DRILL.

APPLICATION FILED NOV. 21, 1921.

Pa-tented July 25, 1922..

Vania/way.

as tance beyond as well understood in the art.

ARTHUR L. HAW KESWORTH, OF BUTTE, MONTANA.

Specification of Letters Patent.

Patented July e5, 1922.

Application filed November 21, 1921. Serial Nb. 516,783.

cation and pointed out in the claims.

The objects of the present invention are: to provide a drill having a detachable bit that is adapted to Wedge tightly on the drill shank during drilling operations, but may be readily detached when'desired; to provide a drill shank and bit having interlocking means between them which also maintain shank and bit against relative displacement under torsional strains; and to provide a drill having such further and other advan: tages as Wlll be better apparent from a detailed description of the invention in connection with the accompanying drawings, in which- Figure l is a side elevation of the drill; Fig. 2 is an elevation with the drill turned to present the dove-tail tongue on the shank and groove in thebit for receiving said tongue; Fig. 3 is an elevation with the drill turned to present the side opposite to that shown in Fig. 2; Fig.4 is a side elevation of the bit detached; Fig. 5 is a. side elevation of drill bar or shank with bit removed; Fig. 6 is a detached elevational view of the bit turned to present the dove-tail tongue in end view; Fig. 7 is a detached elevational view of the bit turned to present the dove-tail groove in end view; Fig. 8 is a bottomplan of the bit; and Fig. 9 is an end view of the shank showing the formations that. cooperate with those on the bit in end view.

Referring to the drawings, 1 represents a drill-bar or shank provided with a central passageway or duct a for the flow of water usually employed in drilling operations The shank is provided at. its bit-supporting end with an inclined tongue 2 tapered toward the outer or bit-supporting end of the shank. The free end of the tongue extends a s ort dis he axis of, the shank, and.

forms the upper bounding well of an in or outer bounding wall 6 ofthe groove 3 has a dove-tail groove 5 (Fig. 5) formed in it, said groove extending downwardly along the face 71 about one-half its length.

A bit 6 is adapted to be passed across the shank 1, and is provided with formations for cooperating with those on the shank just described, said formations consistin of a tongue 7 and adjacent groove 8 ig. 4) complementary to the groove'3 and tongue 2 of the shank. However, the tongues 2 and 7 are made a little shorter than the grooves 8 and 3 which receive them so that said tongues will be wedged into said grooves respectively before reaching the end walls of the grooves. Thus when the bit is in place on' the shank there will be slight clearance spaces .9 and s" between tongue 2 and the end of groove 8 and tongue 7 and end of groove 3 respectively.

The bottom face h of tongue 7 and upper face i of groove 8 are provided with a dovetail tongue 9 and dove-tail groove 10 respectively for receiving their complementary groove 5 and tongue 4 on the shank.

The bit 6 is provided with an axially disposed port a which, when hit and shank are assembled, is in alinement with port a to form a continuous passage through the drill. To assemble the bit and shank the former is passed across the shank so that the tongue 4 enters groove 10 and tongue 9 enters groove 5, at which time tongues 2 and 7 will enter grooves 8 and 3 respectively, and as the bit is moved across the shank the faces 2" and it will ride over the faces a and it until the tongues 2 and 7 are wedged in their respective. grooves. 8 and 3, when further movement will be arrested. Obviously the grooves 5 and 10 extend inwardly toward the axis of the drill farther than tongues 4 and 9, so as not to interfere with the wedging action just described By virtue of the facesi, 1i inclining to.- ward the ends of lthe grooves 3 and 8, any pressure onthe shank 1 in the direction of the bit, such as results in drilling operations, will cause the bit to wedge even more tightly on the shank. However, when it. is desired on the shank under torsional to remove a bit for sharpening or other purpose, itis merely necessary to tap against the bit on the side of the open bottom of the groove 8, when it is readily dislodged.

The bit is held against rotary movement stress by the dove-tail tongues 4 and 9, the side walls of which engage the side walls of the grooves 10 and 5 respectively.

Having described my invention, I claim: 1. In combination with a drill bar or shank, a bit movable across the axis'of'the shank, said bit and drill bar each being pro- 7 vided with an inclined tapering tongue and of the shank, the bottom face of one tongue and the top face of the other tongue each being provided with auxiliary tongues. and the .top face of the one groove and the bottom face of the other groove each being provided with grooves complementary tothe auxiliary tongues, said last mentioned tongues and grooves operating to hold the shank and cutting tool against torsional displacement.

3. In combination with a shank, a cutting tool movable across the axis of the shank,

said shank and tool each being provided with an inclined tapering groove and tongue and groove complementary to the tongue of the opposite member. said tongues and grooves being formed so as to wedge together with vertical pressure along the axis of the shank, the bottom face of one tongue and the top face of the other tongue each being provided with auxiliary dove-tail tongues, and the top face of the one groove and the bottom face of the other groove each being provided with grooves complementary to the auxiliary tongues, said last mentioned tongues and grooves operating to hold the shank and cutting tool against torsional displacement.

4. In combination with a shank, a cutting tool detachably secured thereto, said shank and cutting tool each terminating in scarfs disposed in superposed planes adapted to cooperate to form a scarf-joint. the scarfs of the respective members being formed so as to wedge together on moving one' member across the other and in cooperative relation therewith.

5. In combination with a shank. a cutting tool detachably secured thereto. said shank and cutting tool each terminating in scarfs disposed in superposed planes adapted to cooperate to form a scarf joint, the scarfs of the respective members being formed so as to wedge together on moving one member across the other and in cooperative relation therewith. and means for holding the cutting tool against displacement laterally with respect to the tongues.

In testimony whereof I hereunto afiix my signature.

ARTHUR L. HAWVKESWORTH. 

